/// <summary>
/// Begins a storyboard and waits for it to complete.
/// </summary>
public static async Task BeginAsync(this Storyboard storyboard)
{
await EventAsync.FromEvent <object>(
eh => storyboard.Completed += eh,
eh => storyboard.Completed -= eh,
storyboard.Begin);
}
/// <summary>
/// Waits for the element to load (construct and add to the main object tree).
/// </summary>
public static async Task WaitForLoadedAsync(this FrameworkElement frameworkElement)
{
if (frameworkElement.IsInVisualTree())
{
return;
}
await EventAsync.FromRoutedEvent(
eh => frameworkElement.Loaded += eh,
eh => frameworkElement.Loaded -= eh);
}
/// <summary>
/// Scrolls to horizontal offset asynchronously.
/// </summary>
/// <param name="scrollViewer">The scroll viewer.</param>
/// <param name="offset">The offset.</param>
/// <returns>The task that completes when scrolling is complete.</returns>
public static async Task ScrollToHorizontalOffsetAsync(this ScrollViewer scrollViewer, double offset)
{
if (offset < 0)
{
offset = 0;
}
if (offset > scrollViewer.ScrollableWidth)
{
offset = scrollViewer.ScrollableWidth;
}
var currentOffset = scrollViewer.HorizontalOffset;
// ReSharper disable CompareOfFloatsByEqualityOperator
if (offset == currentOffset)
{
return;
}
if (!scrollViewer.ChangeView(offset, null, null, true))
{
return;
}
if (scrollViewer.HorizontalOffset == offset)
{
return;
}
if (scrollViewer.HorizontalOffset != currentOffset)
{
return;
}
// ReSharper restore CompareOfFloatsByEqualityOperator
await EventAsync.FromEvent <ScrollViewerViewChangedEventArgs>(
eh => scrollViewer.ViewChanged += eh,
eh => scrollViewer.ViewChanged -= eh);
}
/// <summary>
/// Scrolls to vertical offset asynchronously.
/// </summary>
/// <param name="scrollViewer">The scroll viewer.</param>
/// <param name="offset">The offset.</param>
/// <returns>The task that completes when scrolling is complete.</returns>
public static async Task ScrollToVerticalOffsetAsync(this ScrollViewer scrollViewer, double offset)
{
if (offset < 0)
{
offset = 0;
}
if (offset > scrollViewer.ScrollableHeight)
{
offset = scrollViewer.ScrollableHeight;
}
var currentOffset = scrollViewer.VerticalOffset;
// ReSharper disable CompareOfFloatsByEqualityOperator
if (offset == currentOffset)
{
return;
}
//scrollViewer.ScrollToVerticalOffset(offset);
if (scrollViewer.VerticalOffset == offset)
{
return;
}
if (scrollViewer.VerticalOffset != currentOffset)
{
return;
}
// ReSharper restore CompareOfFloatsByEqualityOperator
await EventAsync.FromEvent <ScrollViewerViewChangedEventArgs>(
eh => scrollViewer.ViewChanged += eh,
eh => scrollViewer.ViewChanged -= eh);
}
/// <summary>
/// Waits for the next layout update event.
/// </summary>
/// <param name="frameworkElement">The framework element.</param>
/// <returns></returns>
public static async Task WaitForLayoutUpdateAsync(this FrameworkElement frameworkElement)
{
await EventAsync.FromEvent <object>(
eh => frameworkElement.LayoutUpdated += eh,
eh => frameworkElement.LayoutUpdated -= eh);
}
/// <summary>
/// Waits for the element to unload (disconnect from the main object tree).
/// </summary>
public static async Task WaitForUnloadedAsync(this FrameworkElement frameworkElement)
{
await EventAsync.FromRoutedEvent(
eh => frameworkElement.Unloaded += eh,
eh => frameworkElement.Unloaded -= eh);
}
/// <summary>
/// Waits for the LostFocus event.
/// Note that the event might not be raised if the focus has already been lost or is queued to be lost,
/// so some polling might be advised if that is the case.
/// </summary>
/// <param name="control">The control whoe focuse loss is being awaited.</param>
public static async Task WaitForLostFocusAsync(this UIElement control)
{
await EventAsync.FromRoutedEvent(
eh => control.LostFocus += eh,
eh => control.LostFocus -= eh);
}
/// <summary>
/// Waits for the button Click event.
/// </summary>
public static async Task <RoutedEventArgs> WaitForClickAsync(this ButtonBase button)
{
return(await EventAsync.FromRoutedEvent(
eh => button.Click += eh,
eh => button.Click -= eh));
}
